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Taking Marine Mammals Incidental to Specified Activities; Port Sutton Navigation Channel, Tampa Bay, FL

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Information about this document as published in the Federal Register.

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This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

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National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.


Notice of a proposed modification to a proposed marine mammal incidental take authorization; request for comments.


NMFS received a request from the U.S. Army Corps of Engineers-Jacksonville District (Corps) for an authorization to take marine mammals, by harassment, incidental to expanding and deepening the Port Sutton Navigation Channel in Tampa Harbor, FL (Port Sutton project). On August 18, 2005, NMFS published a Federal Register notice to solicit public comments for the Corps' proposed project and NMFS preliminary determination of issuing an incidental harassment authorization (IHA) to the Corps. Subsequently, the Corps submitted additional information to NMFS on charge weight of the explosives and calculations for impact zones from a similar port construction project that the Corps completed in Miami. Due to the similarity of the geophysical structure and rock substrate between the Port of Miami and Port Sutton, the Corps proposes to modify certain aspects of the proposed project in Port Sutton with the best available scientific information obtained from the Port of Miami project. NMFS is requesting comments on the proposed Start Printed Page 40480modifications to the Port Sutton project and its IHA.


Comments and information must be received no later than August 1, 2006.


Comments on this proposed modification should be addressed to P. Michael Payne, Chief, Permits, Conservation and Education Division, Office of Protected Species, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910. The mailbox address for providing e-mail comments on this action is Comments sent via e-mail, including all attachments, must not exceed a 10-megabyte file size. NMFS requests that comments be limited to the proposed modifications only; comments already submitted during the original public comment will be addressed when NMFS makes a final determination whether an IHA will be issued. A copy of the original application, Environmental Assessment (EA), and documents submitted to support the modifications may be obtained by writing to the address provided or by telephoning the contact listed under the heading FOR FURTHER INFORMATION CONTACT. Publications referenced in this document are available for viewing, by appointment during regular business hours, at the address provided here during this comment period.

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Shane Guan, NMFS, (301)713-2289, ext 137.

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Sections 101(a)(5)(A) and (D) of the Marine Mammal Protection Act (MMPA) (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

An authorization shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s), will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses, and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and reporting of such takings are set forth. NMFS has defined “negligible impact” in 50 CFR 216.103 as “an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival.”

Subsection 101(a)(5)(D) of the MMPA established an expedited process by which citizens of the United States can apply for an authorization to incidentally take small numbers of marine mammals by harassment. Except with respect to certain activities not pertinent here, the MMPA now defines “harassment” as:

any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild [Level A harassment]; or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering [Level B harassment].

Subsection 101(a)(5)(D) establishes a 45-day time limit for NMFS review of an application followed by a 30-day public notice and comment period on any proposed authorizations for the incidental harassment of small numbers of marine mammals.

Summary of Request

On February 26, 2004, NMFS received a request from the Corps for an authorization to take, by harassment, bottlenose dolphins (Tursiops truncatus) incidental to using blasting during enlargement of the Port Sutton Navigation Channel, a part of the Tampa Harbor Federal Navigation Project, in the northern portion of Tampa Bay, Hillsborough County, Florida. The purpose of the project is to enlarge the navigation channel to accommodate larger vessels and incorporate an additional channel segment into the Federal channel. Detailed information of the project description, a summary of the marine mammal species in the proposed project area, and a description of potential effects on marine mammals are provided in a previous Federal Register notice (70 FR 48541, August 18, 2005) and are not repeated here.

Summary of Proposed Modification

Based on previous experience with harbor construction associated blasting in Puerto Rico in 1999 and Miami in 2005, the Corps has developed a set of standard specifications that would be used as general guidelines for the Port Sutton Project. These specifications would modify the existing proposed project plan (including mitigation) in the following ways:

(1) The Corps will not conduct any blasting activities between November 1 and March 31, when the likelihood of Florida manatee (Trichechus manatus latirostris) presence is high within the proposed project area.

(2) The Corps will provide the contractor's approved Blasting Plan to the NMFS, the U.S. Fish and Wildlife Service (USFWS), and the Florida Fish and Wildlife Conservation Commission (FWC) for review at least 30 days prior to the proposed date of the blast(s). The Blasting Plan shall include at least the following information:

(a) A list of the observers, their qualifications, and positions for the watch, and a map depicting the proposed locations for boats or land-based observers.

(b) The amount of explosive charge proposed, the explosive charge's equivalency in TNT, how it will be executed (depth of drilling, stemming, etc.), a drawing showing the placement of charges, size of the safety radius and how it will be marked, tide tables for the proposed blasting event(s), and estimates of times and days for blasting events.

(3) For each explosive charge placed, detonation will not occur if a marine mammal is known to be (or based on previous sightings, may be) within a circular area known as the safety zone. In the absence of acoustic measurements of the shock and pressure waves emanating from the detonations, the following equations were proposed in the Corps' original application and NMFS proposed IHA notice for blasting projects to determine zones of injury or mortality from an open water explosion. The equations, based on Young (1991), were:

Caution zone Radius (R) = 260 x (W)1/3

Safety zone Radius (R) = 520 x (W)1/3

with radius (R) = 260 times or 520 times the cube root of the weight (W) of the explosive charge where R = radius of the zone in ft and W = weight of the explosive charge in lbs/delay. The caution zone represents the radius in ft from the detonation beyond which mortality would not be expected from an open-water blast. The safety zone is the approximate distance in ft beyond which injury (Level A harassment) is unlikely from an open-water explosion. These zones were initially proposed to be used by the Corps for implementing mitigation measures to protect marine mammals.

Upon completion of the Port of Miami harbor construction project, the Corps calculated and analyzed field measurements of acoustic wave pressures during the Port of Miami Project. The results show that the acoustic wave pressures from the Start Printed Page 40481detonation to a distance equal to the caution zone radius plus 300 ft (91 m) dropped down to the level of ambient noise.

Due to the similarity of the geophysical structure and rock substrate between Port of Miami and Port Sutton, the Corps believes the adoption of the Port of Miami pressure measurements to establish safety zones at Port Sutton provides a conservative level of protection for marine mammals. Therefore, the Corps proposes to modify the safety zone radius to the radius of the calculated caution zone plus 300 ft (91 m). This modification will reduce the area of safety zones and make marine mammal monitoring more effective.

(4) Marine mammal monitoring shall begin at least 1 hour prior to the scheduled start of blasting to identify the possible presence of manatees and dolphins. The monitoring shall continue until at least one half-hour after detonations are complete.

Marine mammal monitoring will consist of a minimum of six observers. Each observer will be equipped with a two-way radio that shall be dedicated exclusively to the watch. Extra radio should be available in case of failures. Observers will also be equipped with polarized sunglasses, binoculars, a red flag for backup visual communication, and a sighting log with a map to record marine mammal sightings.

In addition to monitoring from two small boats and from a draw barge, marine mammal monitoring will also include a continuous aerial survey to be conducted by aircraft, as approved by the Federal Aviation Administration.

(5) Detonation events will be halted if an animal is spotted within 300 ft (91 m) of the perimeter of the caution zone (i.e., the safety zone). The blasting event shall not take place until the animal moves out of the area under its own volition, or 30 minutes after the last sighting of the animal.

Endangered Species Act

The Corps is currently working with the USFWS on an ESA section 7 consultation regarding potential take of Florida manatees incidental to the proposed action. No ESA-listed species under NMFS jurisdiction will be affected.

Preliminary Conclusions

NMFS believes that the Corps' proposed modification to the proposed action would not increase the incidental take of marine mammals from its original proposal by number or severity. The newly available information that was used for the proposed modification would provide a better assessment on the potential impacts on marine mammals, and therefore provides more effective mitigation and monitoring measures. NMFS retains its preliminary determination made in its previous Federal Register notice (70 FR 48541, August 18, 2005) that the Corps' proposed action and subsequent modification, including mitigation measures to protect marine mammals, may result, at worst, in the temporary modification in behavior by small numbers of bottlenose dolphins, including temporarily vacating the Port Sutton Channel area to avoid the blasting activity and potential for minor visual and acoustic disturbance from dredging and detonations. This action is expected to have a negligible impact on the affected species or stock of marine mammals. In addition, no take by injury or death is anticipated, and harassment takes will be at the lowest level practicable due to incorporation of the mitigation measures described in this document and the August 18, 2005, Federal Register notice (70 FR 48541).

Proposed Authorization

NMFS proposes to issue an IHA to the Corps for the harassment of small numbers of bottlenose dolphins incidental to expanding and deepening the Port Sutton Channel in Tampa Harbor, FL, provided the mitigation, monitoring, and reporting requirements, along with the proposed modifications, are incorporated.

Information Solicited

NMFS requests interested persons to submit comments and information concerning this proposed modification to the proposed project and NMFS' preliminary determination of issuing an IHA (see ADDRESSES).

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Dated: July 11, 2006.

James H. Lecky,

Director, Office of Protected Resources, National Marine Fisheries Service.

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[FR Doc. E6-11268 Filed 7-14-06; 8:45 am]